I've probably not described it very well in the Subject Heading but we all know that there is a 'rust trap waiting to happen' (and often does) where the rear of the front wing meets the area near the door hinge pillar. Is it called a cloaking panel? What was Mr Issigonis thinking of when he signed off this part of his design?

Anyway, although it's somewhat academic personally, as I'll never intentionally take my car out in the rain.....but I may get 'caught out' sometimes, I'd like to protect my car for future owners so I want to know if it's worth trying to fill the gap with, say, some silicone window sealant or something similar.

I've just ordered a tin of POR 15 Rust preventative paint for the inner wheel arches. My son has used this stuff and swears by it but told me to buy/use a cheap brush to throw away after use, as there is virtually nothing to clean it with and it sets rock hard. I'll let you know on that one! While I wait for the paint to come I've already thoroughly degreased and cleaned the areas, on all 4 wings, I want to paint, hence the consideration of applying some type of sealant that I can perhaps paint over.

I can't help but think that someone must have tried to seal this gap. If so, what did you use? Did it work? Or is it there for a reason and should I just squirt as much waxoyl as I can into it?

Thanks, as ever everyone, in anticipation of your advice/recommendations.

I don’t think there is such a thing as ‘rustproofing ‘ a Minor , but mine were cavity wax injected , the undersides sorted,hammerited and waxoyled to within an inch of their life. Since when they go out in all weathers except when there is salt on the road. They live indoors and are still completely solid, though I do renew the waxoyl regularly.

Whilst the void behind the 'cloaking panel' is a possible rust trap - the Minor was never designed to last as long as it has. In the normal run of things the Minor would have rusted away within a few years of production ending so any long term rust trap voids would not be a consideration. Cars are not designed to last forever - they always have had a design life period.
So whilst overall the Minor was designed by Issigonis not all of the fine detail was from his pen most of it arising from the design team.

It is only the enthusiasts that have kept the Minor alive otherwise it would have been dead and buried years ago.

I do understand what you mean Steve. Just another definition of 'mission impossible' but that's not going to stop me trying or at least slowing the process down!

The guy I bought my Moggy from was very much 'old school' and every time he changed the engine oil he mixed some of it with half a tin of grease and painted the whole of the underside bodywork, excluding the wings. It looks a bit of a mess underneath (polite version!) but run your finger anywhere on the chassis and the metalwork underneath is pristine! The added advantage of this rust prevention....err, sorry, slowing-down system is that everything comes undone very, very easily, as we found out when the rear springs were replaced recently .

A good many modern cars have foam sound insulation fitted in the area behind the front wings next to the A-pillar, and quite often when the underguard is removed, you find it's sopping wet - the foam soaks up water like a sponge, and of course, holds it all against the inside of the wing. Not good for long-term durability!

On my Minor, I try to regularly clean out the void and periodically paint it with Waxoyl black or similar.

I would imagine that silicone sealant lodged in there would eventually allow some water in and trap it there, leading to the inevitable rot.

I heard a while ago of a company (in the Netherlands, IIRC) making underguards for the Minor, but they were rather pricy, at over 100 Euros a pair.

Thanks Chipper. As it happens, I've decided against applying any sealant, mainly on the advice of my son who said pretty much the same as you. At one time he had an oldish Toyota Celica with built-in rust-traps and the members of his owner's club warned him against effectively trapping water inside by trying to seal them.

As I said originally, my car will very rarely (if ever) be exposed to wet conditions so an occasional squirt with Waxoyl should suffice.

Incidentally, I've now applied that POR 15 (wonder if the firm's MD has got that reg. no. ) rust protector which goes on very easily and covers well. It really does what it says on the tin and dries to an absolutely rock hard finish. You could just about hammer nails in with the brush when it has dried!! I can't vouch for its rust prevention properties yet...…...I'll let you know in about 10 year's time